Six at the top is read as a situation in which the cost has already been accepted. The image of wading on until the water closes over the head tells a querent that the course they are considering, or are already committed to, will not be survived intact, and the refusal to attach blame tells them it may be worth doing anyway. Very few lines make that separation as cleanly. The outcome is called evil and the conduct is called faultless in the same breath.
The position is the outer edge of the whole figure, a yielding stroke correctly placed at the top of the upper trigram Dui, past the seat of authority and past any point at which the load could still be adjusted. Great Preponderance has been describing a structure carrying more than it should from its first line onward, and this is where the carrying stops being a structural question and becomes a personal one. What is at stake is no longer the beam. It is the person in the river.
When the line changes, the upper trigram Dui becomes Qian and the figure becomes Coming to Meet, King Wen 44, in which a single yielding stroke appears at the bottom beneath five strong ones. Read from the top of Great Preponderance, that destination is a plain statement of scale. What is given up here is complete, and whatever follows begins again from one small thing entering at the very bottom.